Apparatus for testing thin rubber articles



l Patente-cl` 1l, l v

I UNITED sfirlrrtsV PATENT `Aol-fFic-E 1 2.29293?.v I `1 y M. Youngs.Trenton',-N. J., assigner to Yonngaubber Corp. of N. J., Trenton, N..1.1, a

corporation of'New Jersey i. onglmi application Much so, '1939, serais.

'265,018. Dividedaml this application October 10, 1939, Serial No.298,553'v l v4 claims. Thisl invention relates to new and usefulimprovements in apparatus for testingthin rub.-

ber articles and more particularly for testing -such articles forimperfections,'such as holes and -perforations therein, being a divisionof an application for United States Letters Patent Serial No. 265,018,nled March 30, 1939.4

Concurrently with the drive on the part of Government and varioussociologie associations against venereal diseases, attempts arel beingmade' on the part of manufacturers to' control the manufacture of rubberprophylactic articles and prevent the sale of such articles as may bedefective or imperfect due to the presence of holes or perforationstherein. l With the foregoing in mind, the principal object of thepresent invention is to providefa novel apparatus for testing rubberprophylactic articles whereby any hole or perforation therein, howeversmall, may be readily observed or detected. thus permitting imperfectarticles to be rejected. L

A stili further object of the invention is to provide an apparatus fortesting articles of the type described which is entirely accurateandfoolproof. v

These and other objects and features of the invention and the variousdetails of vits conmeral I designates generally'an endless conveyorcontinuous andvin the direction of the arrows.

The sprocket wheel I is merely an idler and the chain I is driven by thesprocket 2 which is in turn driven-from. a motor I through a suitablebelt, chain or the like 5.

The chain conveyor I' is of the conventional articulated link typecomprising pairs of side bars Y or links l pivotally connected to theadjacent or next pair of lbars or links 6 by means of a pin Iv whichalso carries a roller 8, interposed between 'said side bars or links I,for engagement with the teeth of the sprocket wheels 2 and 3 in theusual manner. Rlgldly secured to the pivots 'I at opposite ends thereofare brackets 9 having a vertical leg 9a and an upper outwardlyprojecting horizontal leg 9b. AA bar or rod III- is securedto thehorizontal legs 9b of each pair of brackets 9 yso as to extendtransversely of the chain conveyor I and beyond each struction andoperation are hereinafter fully set A side thereof.

l Plvotally connected to opposite ends of each cross Bar I 0 by means ofa spindle II as at I2 for swinging movement of a plane perpendicular tothe plane of travel of the chain I is a mandrel or. like support,designated generally as Il, for the thin rubber articles. The mandrelsIl comprise a hollow main body portion Il of suitable material such asmetal and a base or spective of an apparatus contemplated by the presentinvention for testing thin rubber articles; f

Figure 2 is an enlarged transverse view in section through the upper runof the apparatus taken on line 2 2, Figure 1; and' Figure 3 is a viewshowing the manner in which the'present invention operates to affordvisible detection of imperfections in the articles.

The invention is based essentially upon Vthe discovery that bystretching prophylactic articles of thin rubber over a mandrel or othersupporting form and then immersing the same in a bath of liquid, thesaid liquid will pass through even the `mostr'ninute hole orperforationin the article and spread over the interior surface thereof between saidarticle and mandrel producing a comparatively dark spot or area which isreadilyl perceptible to the human eye.

lhub portion I5 of suitable material such as, for

example, ,hard rubber, Micarta, Bakelite, or the like. As shown, themain body portion Il of the mandrel or support I3 is of greater diameterand length than the normal diameter and length of the rubber articles sothat the latter are supported thereon in a relatively stretched state orcondition both lengthwise and laterally, and said body is pressed orotherwise secured upon the adjacent end portion of the base or aperturesI6 therein to permit the passage of air from the interior of the rubberarticles when 'mounting' the same on said body Il of the mandrelsyand inorder that the thin rubber articles will be retained uniformly upon theman- Referring now to thedrawing, there is thus illustrated one form ofapparatus capable of car' rying out the'present invention,` andreferring drels I3 in the desired state or degree of stretch said bodyportions I4 areeachprovided with a -circumferential groove toward oradjacent the base endthereof. This groove is intended to receive theusual bead provided at the open end ofthe rubber articles which are thussecurely particularly.` to Figure l thereof, reference nu- 55 retaineduniformly upon the mandrels and in the stretched state or conditionrequired successfully to carry out the invention.

The base or hub portion I of the mandrel or support I3 is in the form ofa relatively thick sleeve or tube and is journalled upon the pivotallymounted spindle II by means of suitable ball bearing structures I'I soas to permit rotation of the mandrels freely about said spindles. 'I'husthe mandrel I3, including its main body and base portions Il and I5, isfree to rotate about the spindle II, and at the same time, by `virtue ofthe pivotal connection I2 of the spindle II with the bar I0, is movablein a plane perpendicular to the plane of travel of the chain I.

The several mandrels I3 are supported in the desired angular positionlaterally of the chain I by means of tracks or guides I8 disposed atleither side thereof and in subjacent contact with the hub or baseportion I5 of said mandrels, the tracks or guides I8 being stationaryand having a friction surface |80, so that the mandrels I3 are caused toroll therealong and rotate about their supporting spindles I I as theyare advanced by the chain I.

The tracks or guides I8 extend throughout the cycle or course of thechain I except for a relatively short length Athereof in which the thinrubber articles are respectively mounted upon the mandrels I3, thisstation being located adjacent or toward the end of the lower run of thecourse of the said chain I. The tracks or guides I8 are so positionedwith respect to the chain I that their upper surfaces I8a support themandrels I3 in a substantially horizontal position throughout thegreater part of the chain course.

'I'he thin rubber articles are manually stretched upon the mandrels, ashereinbefore set forth, during the course of travel of the chain I nearthe end of its lower run and at this loading station the hubs or basesI5 of the mandrels I3 leave the stationary tracks or guides I8 and areengaged by an endless belt I9. This belt I9 is carried upon main andauxiliary rolls and 2| respectively so as to elevate the upper course ofsaid belt I9 above the level of the track or guides I8 and therebyelevate or incline the mandrels I3 upwardly at an angle of approximatelyto facilitate mounting of the thin rubber articles thereon. Mounting ofthe articles upon the mandrels I3 which rotate about their supportingspindles II is extremely diillcult and in order to prevent such rotationof said mandrels I3 during this loading stage, the belt I9 is driven inthe direction of travel of the chain I and at exactly the same speed assaid chain so that no rotation of the mandrels takes place while incontact with said belt I9, and to insure exact coordination andduplication of the speed of the chain I and belt I9, the latter isdriven from the driving means of the former through a chain, belt or thelike 22.

Upon leaving the belt I9, the mandrels I3, each with an article mountedthereon, engage the tracks or guides I8 and are supported thereby in alaterally projecting horizontal position in which position they arecarried by the chain I about the sprocket wheels 2 and 3 into the upperrun of the course, where they traverse an open trough or tank 23 ofsuitable length and width. In this portion of the upper run over thetank 23 the tracks or guides I8 converge gradually into closer spacedrelation with respect to the chain I and their upper mandrel contactingsurfaces I8a gradually decline outwardly and downwardly until they aredisposed in a substantially vertical plane, thus permitting the saidmandrels I3 to swing downwardly into the trough or tank 23 as shown inFigures 1 and 2 of the drawing. After the mandrels I3 have moved throughthe trough' or tank a .relatively short distance ln the substantiallyvertical position shown in said Figure 2, the tracks or guides I8 andtheir upper surfaces gradually return to their previous relativepositions thus causing the mandrels I3 to be gradually raised or swungupwardly out of said trough or tank 23 into horlzontal position againfor continued movement through the course.

The trough or tank 23 is filled with a suitable liquid such as, forexample, water, and upon immersion of the articles therein as abovedescribed, the liquid will penetrate through even the smallest hole inan article and appear as a relatively dark, readily visible area in theregion of said hole. In its normal condition the liquid, for examplewater, requires a period of time to penetrate the smaller holes which isof too great duration for practical commercial application of theinvention for quantity production work and, in order that the water.will penetrate even the smallest hole in an article in a few secondstime, I reduce the surface tension of the liquid to the desiredextent-or degree. This may be done by heating the liquid or addingthereto a predetermined quantity of a wetting agent such as, forexample, AerosoL In the practical commercial application of theinvention, however, I both heat the water and also add thereto a smallquantity of Aeroso1; and very satisfactory results are obtained by theuse of a bath of water maintained at a temperature of betweenapproximately 100 F. to 110 F. and to which has been added a ten percent solution of Aerosol at the rate of one ounce for each gallon ofwater.

The bath is preferably of such depth and so spaced below the chain Ithat as the mandrels I3 swing downwardly into the same, in the mannerpreviously described, the articles mounted thereon are substantiallyentirely immersed In said liquid for a predetermined thoughcomparatively short period of time and travel as shown in Figure 2 ofthe drawing.

During immersion and travel of the articles through the bath, should anyarticle be imperfect the liquid will pass or seep through- 'the mostminute hole or aperture in the article and spread-out over the innersurface thereof between said article and its supporting mandrel andaround such hole or perforation thus producing a comparatively darkerspot or area, for example, as shown in Figure 3, which is readilyperceptible to the eye, and enables an observer or inspector to discardthat particular article because defective.

While a particular embodiment of the invention has been hereinillustrated and described it is not intendedv that said invention belimited thereto but that changes and modifications may be made andincorporated therein within the scope of the annexed claims.

I claim:

1. Apparatus for testing thin rubber prophy-A carried by said conveyorto swing in planes perpendicular to the planes of movement thereof, saidelements each having a diameter and length l greater than the normaldiameter and length of the articles and each having a circumferentialgroove suitably located therein to receive the open end edge of anarticle to retain the same on the elements in a comparatively stretchedcondition, a trough containing a liquid'bath of low surface tensiondisposed below the conveyor for a portion of the length of its path oftravel, means adjacent the conveyor providing a support for saidelements which engage and roll thereon, said means normally supportingthe elements in positions above and clear of the trough and beingconstructed and arranged to cause said elements to swing downwardly intothe liquid bath in said I l arranged to travel at the speed of travel ofsaid conveyor and in the same direction, so that rotation of saidelements is prevented, to facilitate mounting of the articles thereon.

2. Apparatus for testing thin rubber prophylactic articles to detectimperfections such as holes therein, comprising an `endless conveyor,

means for moving said conveyor continuously in one direction, a seriesof rotatably mounted elements pivotally carried by saidconveyor to swingin planes perpendicular to the planes of movement thereof, said elementseach having a diameter and length greater than the normal diam'- eterand length of the articles and arranged to support the articles thereonin a comparatively stretched condition, a trough containing a-liquidbath disposed below the conveyor for-a portion of the length of its pathof. travel, means adjacent the conveyor providing a support for saidelements which engage and roll thereon, said means normally supportingthe elements in positions above and clear of the trough and beingconstructed and arranged to cause said elements to swing downwardly intothe liquid bath in said trough and return to their normal positionthereabove while traversing the trough so that the articles on theelements are substantially entirely immersed in the liquid which willpass through any hole in an article and produce a comparatively darker,readily visible area in the region of said hole, and other means inadvance of said trough arranged to 'engage and support the elementsduring a portion of their travel with the i conveyor, said other meansbeing constructed and arranged to travel at the speed of travel of saidconveyor and in the same direction, so that rotation of said elements isprevented, to facilitate mounting of the articles thereon.

3. Apparatus for` testing thin rubber prophylactic articles `comprisingan endless conveyor,

means for moving said conveyor continuously in one direction, a seriesof rotatably mounted elements for supporting thereon the articlespivotally carried by the conveyor to Swingin planes perpendicular to theplanes of movement thereof, a trough for containing a liquid disposedbeneath the conveyor for a portion of the length of its path of travel,track means on which the elements roll positioned normally to supportsaid elements insubstantially horizontal positions and being constructedand arranged to cause said elements to swing downwardly into the troughand then return to their normal positions while traversing the trough,said track means being disposed adjacent the conveyor and extendinglengthwise substantially throughout the course thereof, a beltpositioned lengthwise of and adjacent the conveyor along a portion ofits course in advance of the trough and arranged to engage and supportthe elements during travel thereof with said conveyor through saidportion of its course, and means for moving said belt at the speed oftravel of the conveyor and in the same direction thereas so thatrotation of said elements is prevented during support thereof by thebelt to facilitate mounting of the articles thereon.

4. Apparatus for testing thin rubber prophylactic articles comprising anendless conveyor, means for moving said conveyor continuously in onedirection, a series of rotatably mounted elcments for supporting thereonthe articles pivotally carried by the conveyor to swing in planesperpendicular to the planes of movement thereof, a trough for containinga liquid disposed beneath the conveyor for a portion of the length ofits path of travel, track -means on which the elements roll positionednormally to support'said elements in substantially horizontal positionsand being constructed and arranged tocause said elements to swingdownwardly into the trough and then return to their normal positionswhile traversing the trough, said trackmeans being disposed adjacent theconveyor and extending lengthwise substantially throughout the coursethereof, an endless belt positioned lengthwise of and adjacent theconveyor along a portion of its course in advance of the trough andarranged to engage and support the elements at an outwardly inclinedangle during travel thereof with said conveyor through said portion ofits course, and means for moving said belt at the speed of travel of theconveyor and in the same direction thereas so that rotation of saidelements is prevented during support thereof by the belt to facilitatemounting of the articles thereon.

ARTHUR M. YOUNGS.

